污水厂污泥中重金属有效态分布特征研究

通过Tessier逐步提取法结合AAS测试进行Cu、Pb、Cr、Cd、Zn、Ni六种重金属元素的有效态试验,并对污水厂污泥和当地土壤进行了对照分析。分析结果表明,Cu、Pb、Cr、Cd、Zn、Ni在污水厂污泥中主要以不容易迁移的有机态和残渣态存在。Cu、Ni、Zn的可交换态、碳酸盐结合态、铁锰氧化物结合态含量要高于当地土壤,Pb、Cr、Cd等元素易迁移的前三种有效态含量低于当地土壤。当该污水厂污泥用于土壤调节或植物栽培时,有可能引起Cu、Ni、Zn等元素由污泥向土壤继而通过土壤向植物和水体迁移,不宜直接用于土地利用或土壤改良。

Study on Distribution Characteristics of Heavy Metals Speciation in Sludge of Waste Water Plant

In this paper sequential extraction method developed by Tessier, et al. is taken to analyze the chemical speciation of copper, lead, zinc, chromium, cadmium and nickel in sludge. Comparison analyses of sludge and soil show that heavy metals are principally distributed in the organic state and residual state. Movable fractions, especially exchangeable fraction, of Cu,Ni and Zn are higher in sludge than that in local soils, while movable fractions of Pb, Cr, Cd in sludge are equal to or lower than that in local soils. This sludge should not be directly used in land use and soil improvement without treatment.